At least 26 people have been killed in a fire on board an Indian train after its doors were locked overnight leaving passengers no hope of escape.

Officials say many of those trapped suffocated as the result of smoke inhalation after the blaze that took place in the early hours of the morning.

Two children are among the dead whose carriage was derailed from the rest of the train to prevent the fire from spreading.

At least 26 people died in the blaze that broke out at around 3.45am as the passengers were sleeping

Firefighters were forced to pry the locked doors open to retrieve the charred bodies of those who did not survive

Survivors were unable to help all other passengers out of the train through the narrow toilet windows which were the only way to escape

Two children are among those who have been killed in the fire that was reportedly caused by an electrical fault

Survivors were forced to smash windows and jump from the train which was halted one mile from the town of Puttaparthi in Andhra Pradesh state.

Seventy-six people were thought to have been in the carriage when the fire broke out. The blaze reportedly spread to another part of the train but was extinguished.

Firefighters forced their way into the carriage to find many of the bodies lying next to the jammed doors and smashed windows.

'We woke up to the screams of "fire, fire!". Everybody was screaming,' one survivor, identified as Patil, said.

Another, Sharad, recalled: 'We were all asleep. All of a sudden, we all woke up to a burning sensation.'

The man, who was able to save himself and three others by smashing through the windowpane of the cabin's toilet added: 'There was chaos. We realised the bogie (carriage) was burning.'

'But I could not save my wife and maternal uncle.'

Prime Minister Manmohan Singh expressed his 'shock and sadness' at the incident in which at least 26 were killed and more seriously burned

Firefighters and rescue teams had to force their way into the train as the doors had been locked

Initial rescue efforts were hindered by winter fog according to reports, with the first people on scene being those from nearby villages

The charred remains of plastic seats and compartments are all that is left of the carriage where as many as 65 passengers had been sleeping

Some of the victims' bodies have been charred beyond recognition according to officials who say DNA testing may be necessary to identify those dead

Once inside the carriage firefighters discovered the bodies lying next to the carriage's doors and windows

Rescue officials said many bodies were charred beyond recognition and would have to undergo DNA tests to determine their identity.

'Rescue teams have so far recovered 26 bodies from the three-tier coach of the train while five of the eight injured have been admitted to hospital for emergency treatment,' South Western Railway spokesman S. Biswas said.

Prime Minister Manmohan Sigh expressed 'shock and grief at the loss of life in the train accident in Andhra Pradesh' in a statement on his official Twitter account.

The premier addedhe had told
railway and state government authorities 'to extend all possible help to
the victims in rescue and relief operations'.

The carriage was destroyed by the blaze, leaving a mass of twisted metal and melted plastic seats in its wake.

It is not clear how many people had been in the carriage when it caught fire, with some reports suggesting as many as 67 could have been on board.

The coach caught fire in the pre-dawn hours as it travelled from Bangalore to Nanded.

The exit doors of Indian trains are customarily locked at night, reports said, while the carriage windows are covered with bars.

The toilet windows are the only ones that have no bars, though they are considerably small.

The carriage had been separated from the rest of the train to prevent the fire from spreading according to witnesses

It is unclear exactly how many people were travelling in the carriage though reports suggest there were as many as 67

The train was travelling from Bangalore to Nanded when it caught fire near the small town of Puttaparthi in the early hours

Officials were not sure of exactly how many people were in the carriage when it caught fire,or whether they would retrieve more bodies yet

'We were suffocating because we couldn't get the windows open, the windows are really strong,' one young man, who lost his cousin to the flames, told India's NDTV news.

The tragedy comes a little over a year after another train accident in the same state of Andhra Pradesh killed 32 people.

It was not immediately known whether more bodies would be found, police said.

The first people to reach the scene were from nearby villages as initial relief efforts were hindered by winter fog, reports indicate.

Railways Minister Kharge said the railway board chairman would lead an inquiry into the cause of the accident and a more complete report would be issued at a later date.

The engine driver stopped the train when he spotted flames about an hour away from Nanded, a police officer was quoted on The Hindu newspaper website as saying.

Accidents are common on India's railroad network, one of the world's
largest, with some 18 million passengers daily. Most collisions and
fires are blamed on poor maintenance and human error.